Cancer exploded because we bathed the entire population in petrochemical exhaust.
Diesel engines, jet fuel, gasoline, benzene — all Group 1 carcinogens — became ubiquitous in the 20th century. Every highway, every airport, every port, every city bus, every idling truck. Nobody escapes it. You breathe it at school, at work, in traffic, in your neighborhood.
The timeline matches perfectly. As fossil fuel combustion scaled up through the mid-20th century, cancer rates followed. Not because people suddenly started eating badly or living longer — but because the air itself became carcinogenic.
It's not a mystery. It's not complicated. The most well-documented carcinogens on earth were pumped into the air everyone breathes, every day, for 80 years.
And it gets almost no attention — while billions are spent telling people to wear sunscreen and eat more vegetables.
We already know the causes for most cancers. For the most part it's not a mystery, especially now that we can run full DNA panels on people to find genetic markers.
The problem is that even though people know what causes cancer, they take their chances. For instance, smoking. It's not a huge mystery that smoking causes cancer.
You're also ignoring the fact that your timeline also matches up with the medical industry actively studying what causes cancer.
Yes, I'm certain the petrochemicals and bad air and all that contributes to it as well, but it's far from a comprehensive source.
And people replacing whole foods with heavily processed foods, many that contain additives and preservatives and food coloring and flavorings with known carcinogens is definitely a source as well.
And living longer definitely plays into this. The older you live, the greater your chances of getting cancer. It's just a numbers thing.
Dismissing diet and age and pointing only to petrochemicals is very simplistic and doesn't work with reality.